Sister Act!
by Typewriterman
Summary: "The following is a story about Kuroko Shirai, as she finds out a dark secret about her roommate, Academy City's Level 5 Railgun, Misaka Mikoto' Misaka says cryptically in an effort to entice your curiosity to read." Oneshot


**(Disclaimer: For those who have read it earlier, this is a rewritten, proofread and expanded version of "Her Little Sister Can't Be This Cute!". Full details are at the end of the story.)**

Two recommendations for a great read:

Before starting play the OreImo TV size opening, and if you have no idea what that is, just search it on youtube.

At "Dramatic piano music played in Kuroko's mind." Please play the To Aru Kagaku no Railgun OST 07 - Onee-sama...

* * *

**When canon and boredom collide, the story begins…**

As a member of Judgment, Kuroko Shirai had responsibilities outside of her status as a student.

Patrols to make sure curfew was observed, report of small crime and other miscellaneous tasks. There are times that she would even find herself assisting the work of Anti-Skill by controlling crowds at large events and scenes of both crimes and accidents.

To keep Anti-Skill's workload geared toward larger scale criminal activity that affect the safety of large parts of Academy City, Judgment had the authority to act on their behalf for more localized, misdemeanor-type trouble related mainly with the students by district.

Of course, since she was a member of Judgment, ultimately she was still a student. The responsibilities of a student, when there were no dire Judgment activities to be done, would involve things such as homework and take-home projects or other such assignments.

As a student at the prestigious Tokiwadai Middle School though, Kuroko had no concerns for homework because Tokiwadai students weren't assigned anything of that sort.

The school's advanced curriculum and grades hindering solely on examinations or papers was the norm, which would obviously make other students outside of Tokiwadai Middle School cringe at the prospect of such little chance to make up for poor performance.

With such midterm exams and essay submission dates coming in the next week, Kuroko had found herself immersed into an all night session (a poor method of study of course, but it was a last resort tactic since she had been busy with Judgment work for most of the semester), which was why her scant hours of sleep barely felt enough to rejuvenate her energy as she let out a yawn.

Though Judgment members always had work to do, Kuroko was not one to waste a rare free day off from duty, which also coincidentally fell upon a Saturday.

Of the two dormitories attached to the school, Kuroko lived in the one outside of the School Garden, as she was unable to cope with the haughtiness of all of the "princesses" and "maturing ladies of nobility", all polite synonyms of "spoiled rich brats" to be sure, longer than the mandatory few hours during class.

Kuroko—dressed in a short frill-sleeved pink silk negligee and underwear of the same brand—had just woken up from sleeping in her roommate's bed, which was empty because her roommate had left early that morning. It would definitely have been better if the upperclassman girl was there as well, but the leftover warmth would have to serve as an unresponsive albeit decent replacement.

"_What is with you!"_

Inhaling the remaining essence deeply and dreamily with a wide smile on her face, the Kuroko shot up from under the covers when she heard a commotion from outside the door in the hall.

"_Misaka was just trying to…"_

"_Trying to' what? Get seen? Maaa...Don't you realize how crazy things would get if people saw you here right now?"_

"_So…you don't want anyone to see me? Misaka should permanently hide myself?' Misaka says as she becomes downhearte-_

"_Gh! No! I didn't mean it like that!"_

As it was just outside the door, and Kuroko could recognize the voice belonging to her roommate, like a child dumping a plastic toy to regale in the majesty of an actual life-sized tank, the small girl's affection for her pillow-substitute quickly waned. With a bit of effort she stepped out of the bed and groggily walked over and opened the door, not by habit or conscious navigation, but pure instinct in order to receive her dearest roommate back from wherever she coming back from that morning, unaware that there was someone else standing in the hallway.

"Welcome back, Onee-sa…" She began, rubbing her eyes in a delicate manner when she looked up at Misaka Mikoto, wearing the thin sleeveless sweater atop a beige short sleeve shirt and a light brown skirt that was long enough to cover half her thigh that comprised of the Tokiwadai summer uniform and her guest.

She in turn wore something strikingly similar to Mikoto; a thin sleeveless sweater atop a beige short sleeve shirt and a light brown skirt that was long enough to cover half her thigh…the same baggy white socks that hung at mid calf length…

If she didn't know any better, (not to mention if she wasn't so fatigued in thinking that) standing before her was another Misaka Mikoto.

"K-kuroko?" One of the Misakas exclaimed at her appearance and clamored into the room with the other girl in hand. She also pushed the negligee-clad underclassman a bit to the side in order to shut the door with a huff. "Don't you have Judgment duty or anything like that!"

There was an obvious fluster and anxiety coming from the short-haired brunette.

Ignoring a slight pressure in her sinuses, Kuroko failed to register the question, furiously rubbing her eyes second time now as her stare slowly turned and settled on the second Misaka standing next to the first, who for all intents and purposes was her roommate's almost-identical twin.

Both had the uniform of the Tokiwadai Middle School on—which in of itself bore the question that if she weren't already a student how she had never heard of Misaka having a sister before, or whether it meant that she was transferring in to be a student—showing off that they could very well be twins or at least very proportionately similar.

Finished with roaming her view between each twin's physiques, the smaller girl glanced up at the twin that had yet to speak, whose appearance diverged easily with the accessories she was adorned with; a heart-shaped necklace and a pair of military-like electronic goggles resting atop her head and covering her short fringe.

Though she could've been able to tell without either the necklace or the goggles, of course, with those few seconds of observation Kuroko already determined the vast sea of differences between them.

She couldn't well call herself Misaka's roommate/number one fan/secret lover/stalker otherwise.

Such differences between the two was being able to compare the more modest and solemn demeanor between the one and the prideful and direct other, or the innocent and enticing one and the tsun-tsun and enticing other…

"Kuroko, you're drooling!"

Wiping her mouth with her arm, the teleporter turned her attention back toward the girl with furrowed eyebrows aimed at her.

"Onee-sama, is this…your **sister**?" barely outside of a trance, Kuroko's eyes continued to flicker from side to side, between the two Misakas standing before her. "Are you twins? Is she older or are you the older one? Will you both be sleeping in the same bed!"

Feeling that those questions could turn devastatingly sour for her ego, and simply ignoring the third one altogether, the brunette casually made sure that her Gekota phone was tucked deeply into her skirt pocket.

"…" At first she kept quiet because of the technical relation between herself and her clone, so Mikoto begrudgingly sighed and admitted "Yeah, she's my 'sister'…though we're _definitely_ not twins…in fact, she's the younger one here…"

She glanced downwards for a moment to check if the phone was still out of sight.

"Ohhh!" Kuroko's eyes sparkled at the revelation and she began to hop from side to side as though unsure to bet two extremely similar kinds of candy at the store in order to get a closer comparison between the two Misakas.

"Hey, would you stop that blushing? It's embarrassing me…" disgusted by the sight of her roommate's sheer enthrallment at the news, Misaka turned toward her clone. "What the hell? Not you too!"

Clearing her throat, Kuroko stopped just in front of the other Misaka, taking the girl's hand in hers and bowed slightly like a host trying to coax a customer into her club, bringing her lips close to the delicate fingers that neither flinched nor crackled with the sound of electricity at the touch. "Excuse me miss, since I could never conjure any sort of fitting title that encapsulates your all...what's your name?" she asked in a baritone accompanied with a shady looking smile.

Without hesitation the girl stared blankly ahead at Kuroko and responded.

"This Misaka is Misaka 10032', answers Mis-" a hand quickly flew to slap Kuroko's hand away while another moved to cover the dully staring girl's mouth. All the while Mikoto strained a patronizing smile and belted out a nervous laugh while the rest of the clone's mumbled response finished from under her palm.

"Thirty…two…?" Kuroko couldn't help but tilt her head to the side upon hearing the unconventional set of numbers.

"What? Thirty two? No, no, no, no…that's not what she said at all, right?" immediately lying, Mikoto turned toward the Sister but quickly regretted it.

"Indeed that is what this Misaka said' Misaka says to con-fmf…" Mikoto immediately clasped the Sister's mouth again to stop her from deepening the hole they were in.

The anxiety only grew more in Mikoto as the situation continued to get worse.

"Onee-sama, what does she mean by saying her name is-"

"J-Jun! Her name's actually Jun!" Mikoto quickly cobbled up a pseudonym from the clone's established serial number.

Kuroko froze.

The Sister looked at Mikoto with surprise.

"…Misaka…Jun?" Sounding out what her name would thus be, Kuroko smiled at the answer as well as the sight of the two girls standing so closely together before her, hand covering the other's face as though to keep silent some forbidden act going on between them.

Giving a less than virgin-looking smile at the "sisters", Kuroko widened her grin into a thin line as all the possibilities flashed in succession through her mind.

What went through Kuroko's mind was thus.

Since there was an infinite amount of scenarios to play with just one Misaka Mikoto, from hiding her childish underwear and replacing it with recently bought lingerie, taking and framing photos of Mikoto in various situations and intimate moments, ordering products from websites that prompted her virus protection software, inventing anniversaries for them to celebrate…now that it had come to her attention that a Misaka Jun existed as well, a girl who was not only the splitting image of her Onee-sama but was also her younger _sister_, that made the number of the kinds of play that could happen, not only for Mikoto or Jun on an individual basis but also with them together, by doing some simple statistical math of the combinations…_**DOUBLE INFINITE**_!

"Kuro…ko…?" Though she thought that she had seen all of the peculiarities of her roommate, Mikoto had to admit that she had never imagined the small girl being able to make a face like the one currently.

It looked as though the normally twin-tailed girl was going through a brain freeze and at the same time was given the results of the extremely difficult test she believed she had passed with flying colors and saw that she failed miserably because she forgot to write her name.

Simply awed by the vacant look in the girl's face, Mikoto removed her hand from her Sister's mouth and took a closer look to see if her roommate was even breathing at this point.

"Perhaps this person is less than enthused about my appearance, Onee-sama?' Misaka hypothesizes upon comparing the level of interaction between how she interacts with this Misaka to how she interacts with you."

A shock rushed through Kuroko's whole being, but Mikoto's attention was turned toward the other Misaka to assuage her sister's concerns to notice the involuntary twitch.

'_She calls her sister "_**Onee-sama**_" as well!'_

The pressure in her sinuses finally exploded as a short stream of red shot out of her nose, causing a disgusted yelp from Mikoto as she warily pulled her "younger sister" a step back.

Dramatic piano music played in Kuroko's mind.

Kuroko shuddered at the wonderful feeling flowing down her spine that came from seeing such a wonderful display from her roommate and idol. "O…nee…sa_maaaaa_…" she moaned out with salivation and a throaty exhale, using the term in a way far different in connotation than when the other Misaka used it.

Her fingers flitted about in all directions in an inhuman manner, like octopus tentacles writhing about to attack a delicious looking crab hiding in the coral reef as she raised her hands, palms aimed in the direction of the sisters.

Simply put, Kuroko curled her lips into a lecherous smile and eyed the girls in front of her carnivorously.

"LETMETOUCH-**NO**-HUGHERATLEASTONCETHENI'LLBESURETOGIVEYOUA-'HUG'-ASWELLSOYOUDON'TFEELLEFT-OWWWWWWWWWWWWWWWW-AGGGHHHHHHHH!"

A hole had opened up in the room as a result of the explosion, and to this day no passersby outside the dorm had any sort of explanation as to what happened.

As the smoke cleared, a rumor spread throughout Academy City that a doppelganger was seen and what followed was a disaster that allegedly caused hundreds of deaths but was covered up. Of course, it was simply a rumor spread onto the internet and forums.

The Anti-Skill officers and Judgment members who poured into the Tokiwadai dormitory in response to the fire alarms, and the students who rushed out to escape the ceiling sprinklers, could only be amazed that the building managed to hold its structure from even the reverberations that followed minutes after the explosion.

* * *

In a certain hospital ward, wrapped from head to toe in bandages and casts to support proper restructuring of her spine, Kuroko Shirai woke up to see a white ceiling above her.

It was most definitely not the first time she had seen such a ceiling before, since as a member of Judgment, Kuroko got herself injured quite often.

Though with a wince of pain despite the obvious pain medications that were coursing through her body, she found that she somewhat still felt all of her limbs and had the ability to move her fingers and toes. The medical bed sheets she lay upon gave a scratching sound against her patient's scrubs, the bandages around her body and themselves when she attempted her little experiment. The bandages that covered even her face ruffled about with every soft breath she took.

Taking a moment in order to try remembering how she got into the hospital in the first place, something that made her draw only a series of blanks, she heard a sound that was unlike the sound of her breathing, or the sound of the bandages that ruffled while she breathed. It was also different from the sound of the bed sheets that rubbed against her patient's scrubs and bandages from any sort of movement to adjust herself.

The sound was that of something soft being cut. Finding that her bed was slightly elevated on her upper torso, she found the source using her eyes and found a brunette haired girl wearing a Tokiwadai Academy uniform peeling a number of fruits onto a plate.

"Onee…sama…?" Kuroko groaned out, calling the attention of the Electromaster.

"Hey there, Kuroko, how are you holding up?" Mikoto, with a pause in her ministrations offered a soft smile toward the immobile girl.

The look of concern on her roommate's face had somewhat troubled Kuroko, as though it was her fault that such a sad appearance had taken residence there. "Where's your sister? Where's…Jun…?"

"…" Mikoto only chuckled at the question, lowering her gaze down for a moment before looking at Kurko again. "You were mumbling that name all night, Kuroko. Something about there being two of me?" To this, Mikoto gave an amused laugh and sighed. With another breath, Mikoto's hazel eyes settled on the immobilized girl with a dangerous look while digging the knife in her hand through the pear, allowing the juices to drip onto the plate with slow uneven patters.

"**That. Was. Only. A. Dream. **Right, Kuroko?"

"A dream?" Relief softened the tension in the small girl's shoulders as worries about what to do with two Misaka Mikoto's existing suddenly drifted away. In all honesty, she wouldn't have known what to do in such a heavenly situation.

Her smile unseen under the bandages, Kuroko Shirai nodded as best she could under the circumstances. "Though that's sad to hear…" she said with increasingly heavier eyes. No matter, there was a lingering sense of happiness as though some beautiful ideal scenario had happened in a dream but she had woken up and it was lost in exchange for her regained consciousness. "… by the way, Onee-sama…I…can't seem to recall, but, what was the reason that I was…sent to the hospital again…?"

"You walked in on me showering and I shocked you and since you were wet, it caused some extensive damage…" Mikoto smiled.

The answer seemed almost too quickly offered and practiced.

"Hmmmm…I see…that seems about right." Kuroko smiled back from under the bandages.

That response seemed too accepting of such an answer.

"Misaka...Jun..." Outside of the hospital room, Misaka 10032 smiled warmly before walking down the hallway.

The frog-faced doctor standing in front of the door on the other hand, who saw the clone walk away to her room then back at the chart of his patient named "Shirai Kuroko", was perplexed by such a happy-go-lucky ending, but ultimately didn't mind such a result from happening.

Even though he was known as "Heaven Canceller", fourth degree electrical burns were still taxing to operate on but of course not an impossible feat to accomplish.

* * *

**Between the Lines**

Two men were sitting in comfortable chairs across from each other in a very distinguished looking office.

Wood paneled and carpeted in the finest materials, a number of frames full of certificates, degrees, accomplishments and photographs adorned the walls in a manner that was proud in declaring "This is an austere place".

Four large floor-to-ceiling windows were situated behind a wide mahogany and very detailed desk to let in the daytime, flanked by a pair of curtains that had to be of the finest material, given the luster and sheen that they had in reflecting the sunlight.

An oval-shaped carpet could be found in the center of this office, and on either focus of the oval were large leather chairs that would seem to just invite anyone who came in to the office to sit and recognize its plush yet firm feel.

Wearing suits and placing some files on the top of the desk situated just a few feet away from them, they have just finished discussing a very high class affair.

Obviously, a very amiable outcome has come about from their talk as the older of the two men offers a crystal glass and picking another one up fills each glass about halfway with whiskey.

Normally business transactions and agreements happened with at least one lawyer present, or amongst a board of trustees since it involved money in order to note down the legal details of the matter so neither side felt that they were shorted once contracts had been signed.

Today's discussion between the two men however did not involve any of that as that was all taken care of by each side's lawyers and specialists beforehand. Today the two men sat in their chairs drinking whiskey simply to celebrate the success of the deal already made.

"I'm very happy that your company has decided to invest in our school." The older man gave a boastful chuckle while raising his glass. His brown suit jacket was fitted in a way that clung tightly to the large man's body.

"It's not a problem at all, Chairman Unabara. After all, I was once a student myself in Academy City as well."

Modestly waving off the heavy gratitude with a polite shake of his head, the younger man smiled despite the obvious embarrassment that showed on his face.

"As a matter of fact, to show my sincerity you can expect the first half up front right away!"

A haughty laugh is shared between the two men as their glasses clink from their informal toast. "I've heard about the recent damage that happened at one of your dorms. How about I help you repair it? Or even better, renovate it?"

"No, no, please don't go to too much trouble, your charitable offer to help with the repairs is more than gracious enough, Mr. Lifeli-" the older man was stopped as a hand was raised to his face.

"_First_ off, Chairman Unabara, I'm not one for philanthropy." The younger man says in a stern tone.

Though suddenly serious, what he says is not meant to be taken as a threat. It is simply a statement said in a stern way to prevent any future misinterpretations of the man's character.

The older man simply nods.

"Second, just call me by my given name, Galen." Returning his hand to his side, the younger man chuckled with a smile after taking a sip. "Mr. Lifeline is my _father's_ name, you see…and besides, don't you consider us two friends already?"

There is a bit of apprehension at the one sided declaration of what their relationship is, but the Chairman lets it pass. It was one thing to suddenly interrupt a person of his status when he was speaking, but at least the young man called Galen knew to show respect to Unabara's position.

If anything, the effects of the whiskey could always be a culprit to this strange affair of the traditional conversation amongst people of their class.

"Yes, yes, of course." It was the older man's turn to show his embarrassment as he nodded his head and took a sip of his drink.

A small creak brought his attention to in front of him as the leather chair was pushed down by the man before him now standing up.

In his crisp dark black suit, he looked quite imposing despite the friendly smile and neatly cut black hair. It took a moment for the Chairman's mind to catch up but with a small degree of difficulty, the older man stood up as well.

"To the pursuit of knowledge and the continuing progress of science!" the man called Galen declared.

"Yes, and to our partnership as an example for all of Academy City and the World to follow!"

Both men nodded at each other's understanding, and a sharp clink of their glasses followed.

"To Tokiwadai and Kihara International!"

* * *

**Author's notes:**

- 32 is "san-jyu ni" in Japanese, so that's where "Jun" comes from.

- So as stated in the beginning, this one-shot is a rewritten "Her Little Sister Can't Be This Cute!" Not only do I feel the length makes it a more enjoyable read, inspiration from a number of sources, from other To Aru fics recently uploaded to fics from other series (and the great quality and work ethic they have *cough*Allora Gale*cough*Cun*cough*Fukou da*cough*) simply drove me to do better than not only my first To Aru Majutsu no Index fic "Her Little Sister Can't Be This Cute!" but to postpone/cancel my current series "Joint Experiment" in favor of a non-crossover series.

The title of this fic by the way, comes from my love of puns and its greater flexibility in use for the story.

Using this one-shot as a jumping off point, I've been writing a multi-chapter fic in-between school and work and summer job/internship searching that I hope you'll read and enjoy as fellow To Aru fans.

With all that said, please stay tuned for "Sister Act!-!" coming soon.

- All characters belong to Kazama Kamachi and Kiyotaka Haimura as author and illustrator, respectively.


End file.
